we are given
[tex] BQ=10 [/tex]
and we have to find BF
we know that
point Q is centroid
and centroid always leaves median in 2:1
so,
[tex] BQ=\frac{2}{3} *BF [/tex]
now, we can plug BQ=10
[tex] 10=\frac{2}{3} *BF [/tex]
we can solve for BF
[tex] BF=10*\frac{3}{2} [/tex]
so, we get
[tex] BF=15 [/tex]..............Answer